Gyro is Duckburg's most famous inventor, even though his inventions don't always work the way he wants them to. His outrageous productivity is presented as a factor in the quality of his inventions; because he always comes up with new ideas, the fact that his inventions often lack an important feature, will often cause trouble for Scrooge or Donald who have bought the invention. He is known as being good-natured towards others. Gyro is often assisted by his Little Helper (or just "Helper"), who is a small anthropomorphic robot with a light bulb for a head.[1] Besides Little Helper, he has also a "thinking cap", a hat shaped like a combination of a roof-top and a nest, with three black birds living in it. Wearing this thinking cap helps Gyro figure out particularly difficult problems, but it only works if the birds are currently nesting in the cap. Some stories have involved the birds leaving Gyro's thinking cap, resulting in the cap becoming ineffective.

Some of Gyro's relatives include his father Fulton Gearloose, his grandfather Ratchet Gearloose, and Newton Gearloose, his nephew. Occasionally there have been stories about Gyro's girlfriend Matilda. In some stories, Gyro's primary rival is Emil Eagle, although he is also antagonized by the Beagle Boys and Magica De Spell.[2] With his inventions, he is also a very important ally of Donald Duck's alter ego, Paperinik, in the Italian Disney comics. Consistent with the two "G's" in his name, he had bins on his shelves containing odds and ends, which he labeled "Gewgaws", "Gimcracks", "Gadgets" and "Gizmos".

Gyro made his first animated appearance in a 1950' full length movie. On the Sport Goofy Soccermania television special with only one line of dialogue, voiced by Will Ryan: "Scrooge parting with a million dollars?", in the subsequent 1987 animated seriesDuckTales, Gyro became a regular character, with Hal Smith supplying his voice while Barry Gordon records it in several episodes. Among Gyro's noteworthy inventions in the series was the creation of the GizmoDuck suit, intended to be worn by a security guard for Scrooge McDuck's Money Bin. Although Gyro's shop and house are on the south side of Duckburg, he was born on the north side — a sign marks his birthplace and mentions one of his inventions — topless hats.[3]

In high school, young Gyro was a baseball pitcher with his "madball" pitch — actually only a straight-ball pitch. When Gyro is forced to pitch for the Northside, pitting an "unhittable" baseball against another of his inventions, an "unmissable" baseball bat made for the Southside team, the result is total chaos.[4]

Gyro is a classic eccentric genius-once he actually persuaded Duckburg citizens to rebuild it into a climate controlled City of the Future! Unfortunately for Gyro, his ideas worked too well-Donald Duck only worked 1 hour a day and spent 23 hours sleeping which left him more grouchy than normal, while Uncle Scrooge McDuck robot made him so much money that it actually filled up his money bin to the point where McDuck could not even burrow into his money! The final straw came when Gyro Robot helper makes a robot to replace Gyro as an inventor! Realizing Duckburg isn't ready for the future, Gyro turns Duckburg back to its old self.[5]

In the Toontown universe, Gyro created a robot that, when Scrooge accidentally wired it incorrectly, made the Cogs, the main antagonists of the game. They are grim businessmen-like robots who can't take a joke, so to take care of the infestation, the Toons (the main protagonists of the game), destroy them with gags, such as squirting seltzer water and throwing pies at them.

Fulton Gearloose is the son of Ratchet Gearloose and the father of Gyro Gearloose. He was first mentioned in Guardians of The Library in Uncle Scrooge Adventures #27[6] as the inventor of The Junior Woodchucks Merit Badge, as well as the first person it was awarded to (for inventing it). He first appeared in person in The Life and Times of Scrooge McDuck Part 10 as a young child and one of the first three Junior Woodchucks. He appears as an adult in the story Gyro's First Invention.

Newton was a fan of his uncle's work, and wanted to be an inventor like him when he grew up. Newton was also a Junior Woodchuck, as well as a friend of Huey, Dewey and Louie. Newton also went by the nickname "Giggy."

After the early 1970s, Newton ceased appearing in new North American Disney comics. He continued to be used in some Italian and Danish-produced Disney comics into the late 1990s.

There was a similar character in the Ducktales episode "Superdoo", like Newton he was also in the Junior Woodchucks. Though his name is never spoken he does bear a physical resemblance to Newton Gearloose.